with Jeff Gray and Ira Baxter

Robert Tairas

Software Composition and Modeling Laboratory

Department of Computer and Information SciencesUniversity of Alabama at Birmingham

S o f t C o m

Visualization of Clone Detection Results

Eclipse Technology Exchange Workshop

OOPSLA 2006Portland, Oregon

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Code Clones

A sequence of statements that are duplicated in multiple locations in a program

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Source Code

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ClonedCode

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Clones in Source Code

Copy-and-paste parts of code from one location to another The copied code already

works correctly No time to be efficient

Research shows that5-10% of large scalecomputer programsare clones (Baxter, 98)

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Source Code

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Supporting Tool: CloneDR

Commercial clone detection tool developed by Semantic Designs

Finds clones by examining the abstract syntax tree representation of a program

Java version freely available at:http://www.semanticdesigns.com/Products/Clone/register-download.html

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Supporting tool: AJDT Visualiser Plugin Part of the AspectJ Development Tools

(AJDT) project AJDT Visualiser website:

http://www.eclipse.org/ajdt/visualiser An extension point to pass information:

Bars:Implement

IContentProvider

Interface

Stripes:Implement IMarkupProvider Interface

Visualiser View

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Clone Detection Results=== Tree Clone Tuple ====Tuple with 7 clones, 3 parameters; similarity = 0.9873417721518988#4 #10f577d0 #97986c0

Clone 1: 6 lines from Line 43 to 48 File: c:/temp/runtime-EclipseApplication/JHotDraw/src/org/jhotdraw/contrib/WindowMenu.javanew AbstractCommand("Cascade", newEditor) { public void execute() { WindowMenu.this.desktop.cascadeFrames(); }

public boolean isExecutable() { return super.isExecutable() && (WindowMenu.this.desktop.getAllFrames().length > 0); }}

--------------------------------------------------------------------------------#4 #10f577d0 #979d860

Clone 2: 6 lines from Line 51 to 56 File: c:/temp/runtime-EclipseApplication/JHotDraw/src/org/jhotdraw/contrib/WindowMenu.javanew AbstractCommand("Tile", newEditor) { public void execute() { WindowMenu.this.desktop.tileFramesHorizontally(); }

public boolean isExecutable() { return super.isExecutable() && (WindowMenu.this.desktop.getAllFrames().length > 0); }}

--------------------------------------------------------------------------------#4 #10f577d0 #9e77f40

Clone 3: 7 lines from Line 52 to 58 File: c:/temp/runtime-EclipseApplication/JHotDraw/src/org/jhotdraw/contrib/CTXWindowMenu.javanew AbstractCommand("Cascade", newEditor) { public void execute() { CTXWindowMenu.this.desktop.cascadeFrames(); }

public boolean isExecutable() { return super.isExecutable() && (CTXWindowMenu.this.desktop.getAllFrames().length > 0); }} …

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Process

Detection Info View

DetectedClones View

DetectedClones View

Config Wizard

Results Text File Parser

CloneDR

EclipsePlatform

Clone Detection Results Plugin

AJDT Visualiser Plugin

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1. Initially, user is assisted by detection process configuration wizard.2. CloneDR executes and generates a text file containing its results.

These results are parsed by the plugin.3. Detection statistics sent to information view and detected clones

sent to both textual and graphical view (step 3).

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Configuration Wizard

The detection of clones can run on all files or just on pre-selected files

The detection settings for CloneDR are also set in the wizard

Wizard generates a configuration file that will be used by CloneDR

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Detection Information Statistical information

about the clone detection procedure itself in addition to the configuration settings are displayed in the clone detection results information view.

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List of Clones Clone information:

grouped by similarity source file starting line number ending line number

Not new, Simian and SimScan plugins also provide similar reporting

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Visualiser View Bars: Source files Stripes (Kinds): Clones Mouse over:

Length of clone Other clones in the same

clone group

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Visualiser View

Additional Options: Display all bars containing the same clones as in

the selected bar Display all bars containing the selected clone Open the file containing the selected clone Open all files containing clones in the same clone

group as the selected clone

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Clone Refactoring

The Big Picture

RefactoredSource Files

Clone Detection

Detected Clones

Clone Analysis

Selected Clones for Refactoring

OriginalSource Files

Visualization /User Interaction

Programmer

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Case Study

Performed on open source applications JavaGenes, scientific evolutionary software JHotDraw, a GUI framework

Understanding the results Clone group in the same class (JavaGenes)

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Case Study

Understanding the results (continued) Ubitiquous clones (JHotDraw), methods that:

return a new Rectangle object draw two ovals (including setting their colors) setting the undo and redo flags for the drawing view

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Future Work

A more structured view of the source code files For OO languages, classes could be

displayed in UML-like form.

Demarcation of methods in bars representing source files Displaying the borders of methods in

the view can assist in determining which clones are method-level clones.

Tighter integration of CloneDR in Eclipse Simplify and speed up the detection

and visualization process. CloneDR

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Thank you. Questions?

Visualization of Clone Detection Results: http://www.cis.uab.edu/tairasr/visual

Clone Detection Literature: http://www.cis.uab.edu/tairasr/clones/literature

SoftCom Laboratory: http://www.cis.uab.edu/softcom